The present invention relates generally to gas generating systems utilizing a pyrotechnic initiator for initiating operation of a gas generating system. In some gas generating system designs, the elevated pressure produced during combustion of gas generant materials may tend to produce a bowing or distension of portions of the system housing. This expansion of the housing may stress the gas-tight seals which seal possible undesirable leakage paths out of the housing. The stressing or failure of these seals may result in leakage of generated gases and reduced pressure during filling of an associated airbag, for example. Thus, a need exists for improved structures and methods for helping to ensure housing integrity during operation of the gas generating system.